What is the difference between fierce and rage?

Fierce is being intensely aggressive and rage is out of control anger.

Fierce to me is strong, extreme determination. Rage is terrible extreme anger.

fierce – passion & strength & rage – uncontrollable anger 

Fierce can be used in a sense that someone is determined like sports for example just because an athlete is fiercely competitive doesn’t mean they’re angry. Rage stems from anger hostility ect…